中文摘要：

以本实验室自行创制的云烟87八倍体（2n=8x=96）为母本，L-8四倍体为父本进行杂交，成功获得烟草六倍体（2n=6x=72）植株。经观察统计其花器官特征，花粉特征，并通过体外萌发及杂交试验对其育性进行初步研究。结果显示：烟草六倍体花蕾和花药明显大于云烟87四倍体×L．8四倍体杂交组合四倍体（简称四倍体杂种）后代的花蕾和花药，但花粉量较少；其花粉体外萌发率仅9．78％，明显低于四倍体杂种；六倍体花粉在六倍体及云烟87四倍体柱头上只极少量萌发并穿过花柱；以六倍体为父本，与云烟87四倍体烟草品种杂交以及六倍体自交，不能坐果；而以六倍体为母本、云烟87四倍体为父本可得到一定量种子，其单果种子数与杂种四倍体作母本、云烟87四倍体为父本时差异不大，但发芽率只有21．2％。这表明本研究中的六倍体植株作父本不育，而作母本具有一定的育性，后续研究利用中可将其用作母本。

英文摘要：

Tobacco hexaploid plants were obtained successfully by crossingYunyan87 octoploids （2n=8x=96） with L-8 tetraploids, with octoploids as maternal parent. Fertility was studied with traits of flower and pollen, pollen germination in vitro and cross experiment. Results showed that： flower buds and anthers of hexaploid tobaccos were bigger than those of tetraploid tobaccos, with less amount of pollen. Under in vitro conditions, pollen germination rate of hexaploids was only 9.78%, significantly lower than that of tetraploid. Only a very small amount of hexaploid pollen could germinate on Yunyan87 stigma. There was no fruit when hexaploid as male parent while only some mature seeds were harvested when hexaploid as maternal parent. Germination rate of these seeds was only 21.2%. Our data suggested that hexaploid tobacco plants was male sterile and could be used as female parent in future breeding and genetic study.